7.8. The measurement of the width will be taken at the widest point of the complete wheel above hub level. 7.9. Wheel fixing by bolts may be freely changed to fixing by pins and nuts. 7.10. Must have tyres complying with Ch. 8.
7.11. The approved quantity of tyres must be detailed in the Official Documents. The maximum number allowed will not exceed 10 tyres( unsealed surfaces) and 12 tyres( sealed surfaces and all Single Venue Stage Rallies not covered by a Master Agreement) for Rallies up to 45 planned competitive miles. For Events over 45 planned competitive miles an additional 2 tyres may be added for each return to service after 45 planned competitive miles during the Event, but these may not be used prior to the relevant service point.
a.
b.
In the event of an extreme weather situation( defined as: Temperatures below 0c or over 28c within the 24 hour period prior to the start of the event, or snow fall within the same 24 hour period or during the running of the event), the Clerk of the Course may request the ASN Steward to suspend the tyre allowance on the grounds of safety.
Where there is significantly heavy rainfall and the Clerk of the Course( of a Sealed surface Event and all Single Venue Stage Rallies not covered by a Master Agreement) may issue a Bulletin with the approval of the ASN Steward, declaring a ' wet ' Event. Following which, the use of wet tyres will be permitted outside of the specified allowance on the grounds of safety.
c. Competitors found to be in excess of the tyre limit are to be penalised in accordance with App. 8( u) or App. 14( v) as applicable.
7.12. The use of any device for maintaining the performance of the tyre with an internal pressure equal to or greater than atmospheric pressure is forbidden.
7.13. The interior of the tyre( space between the rim and the internal part of the tyre) must be filled only with air or nitrogen. This does not preclude the use of inner tubes.
7.14. The use of tyre heating devices is prohibited.
7.15. For all unsealed surface Stage Rallies approved by the ASN pursuant to App. 1 Arts. 1.10 and 1.11( forest estates) only those tyres specified in Ch. 8 List 6 are permitted.
8. Braking Systems
8.1. Braking systems may be modified including fitment of uprated components conversion of drum brakes to disc brakes and use of alternative friction materials.
8.2. The use of non-metallic brake discs is not permitted.
9. Fuel Systems
9.1. If the filler cap is of the quick release type or where the Vehicle has been fitted with a non-standard filler be fitted with a recessed fuel filler cap.
9.2. Fuel lines may be installed within the Driver / Passenger compartment on safety grounds
9.3. Cars must be fitted with a self-seal connector of a type complying with Ch. 7. Except as provided for in Ch. 7 App. 1 Art. 1.5 Vehicles issued with a current Competition Car Log Book / Vehicle Passport prior to 1st Jan 2009 are not required to have a self seal connector
10. Electrical 10.1. There are restrictions concerning the use of auxiliary lights which are detailed in the sporting regulations.
Motorsport UK National Competition Rules 2026 Edition 1
Chapter 13 Appendix 16- Special Stage Rally Cars 504